/*
Copyright 2006 Jerry Huxtable

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package com.jhlabs.image;

import java.awt.*;
import java.awt.image.*;

// TODO: Auto-generated Javadoc
/**
 * The Class ShearFilter.
 */
public class ShearFilter extends TransformFilter {

	/** The xangle. */
	private float xangle = 0.0f;
	
	/** The yangle. */
	private float yangle = 0.0f;
	
	/** The shx. */
	private float shx = 0.0f;
	
	/** The shy. */
	private float shy = 0.0f;
	
	/** The xoffset. */
	private float xoffset = 0.0f;
	
	/** The yoffset. */
	private float yoffset = 0.0f;
	
	/** The resize. */
	private boolean resize = true;

	/**
	 * Instantiates a new shear filter.
	 */
	public ShearFilter() {
	}

	/**
	 * Sets the resize.
	 * 
	 * @param resize
	 *            the new resize
	 */
	public void setResize(boolean resize) {
		this.resize = resize;
	}

	/**
	 * Checks if is resize.
	 * 
	 * @return true, if is resize
	 */
	public boolean isResize() {
		return resize;
	}

	/**
	 * Sets the x angle.
	 * 
	 * @param xangle
	 *            the new x angle
	 */
	public void setXAngle(float xangle) {
		this.xangle = xangle;
		initialize();
	}

	/**
	 * Gets the x angle.
	 * 
	 * @return the x angle
	 */
	public float getXAngle() {
		return xangle;
	}

	/**
	 * Sets the y angle.
	 * 
	 * @param yangle
	 *            the new y angle
	 */
	public void setYAngle(float yangle) {
		this.yangle = yangle;
		initialize();
	}

	/**
	 * Gets the y angle.
	 * 
	 * @return the y angle
	 */
	public float getYAngle() {
		return yangle;
	}

	/**
	 * Initialize.
	 */
	private void initialize() {
		shx = (float)Math.sin(xangle);
		shy = (float)Math.sin(yangle);
	}
	
	/* (non-Javadoc)
	 * @see com.jhlabs.image.TransformFilter#transformSpace(java.awt.Rectangle)
	 */
	protected void transformSpace(Rectangle r) {
		float tangent = (float)Math.tan(xangle);
		xoffset = -r.height * tangent;
		if (tangent < 0.0)
			tangent = -tangent;
		r.width = (int)(r.height * tangent + r.width + 0.999999f);
		tangent = (float)Math.tan(yangle);
		yoffset = -r.width * tangent;
		if (tangent < 0.0)
			tangent = -tangent;
		r.height = (int)(r.width * tangent + r.height + 0.999999f);
	}

/*
	public void imageComplete(int status) {
try {
		if (status == IMAGEERROR || status == IMAGEABORTED) {
			consumer.imageComplete(status);
			return;
		}

		int width = originalSpace.width;
		int height = originalSpace.height;

		float tangent = Math.tan(angle);
		if (tangent < 0.0)
			tangent = -tangent;
		int newWidth = (int)(height * tangent + width + 0.999999);
		int[] outPixels = new int[height*newWidth];
		int inIndex = 0;
		int yOffset = 0;
		for (int y = 0; y < height; y++) {
			float newCol;
			if (angle >= 0.0)
				newCol = y * tangent;
			else
				newCol = (height-y) * tangent;
			int iNewCol = (int)newCol;
			float f = newCol - iNewCol;
			f = 1.0 - f;

			int outIndex = yOffset+iNewCol;
			int lastRGB = inPixels[inIndex];
			for (int x = 0; x < width; x++) {
				int rgb = inPixels[inIndex];
				outPixels[outIndex] = ImageMath.mixColors(f, lastRGB, rgb);
				lastRGB = rgb;
				inIndex++;
				outIndex++;
			}
			outPixels[outIndex] = ImageMath.mixColors(f, lastRGB, 0);
			yOffset += newWidth;
		}
		consumer.setPixels(0, 0, newWidth, height, defaultRGBModel, outPixels, 0, newWidth);
		consumer.imageComplete(status);
		inPixels = null;
}
catch (Exception e) {
	e.printStackTrace();
}
	}
*/
	
	/* (non-Javadoc)
 * @see com.jhlabs.image.TransformFilter#transformInverse(int, int, float[])
 */
protected void transformInverse(int x, int y, float[] out) {
		out[0] = x + xoffset + (y * shx);
		out[1] = y + yoffset + (x * shy);
	}

	/* (non-Javadoc)
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		return "Distort/Shear...";
	}

}
